While Earth is rightly seen as the UNSC's commercial, political, and cultural center; Reach is undeniably the hub of its military power.

The ε Eridani fleet is a full strength Carrier Group with the supercarrier UNSC Trafalgar at its core. The planet itself has a semi-mobile array of 20 Orbital Defense Platforms, and they are in turn defended by multiple wings of single ships and tactical multi-role craft.